In the field of coupling devices, it is well known that there are many ways to accomplish the coupling of two conduits. These methods vary not only for various applications such as low pressure versus high pressure, but also for the materials from which the two conduits are fabricated. For applications of coupling devices for coupling a rigid pipe, such as fi6ricated from a metal composite, to a flexible pipe, such as plastic or rubber, several different devices have been used heretofore. Typical of the art are those devices disclosed in the following United States Letters Patents:
Patent No. Inventor(s) Issue Date 3,211,476 J. B. Wagner Oct. 12, 1965 5,190,323 H. Oetiker Mar. 2, 1993 5,207,460 H. Oetiker May 4, 1993 5,295,718 D. D. Bartholomew Mar. 22, 1994 5,380,050 J. D. Sanders, et al. Jan. 10, 1995 5,775,740 K. Fukaya, et al. July 7, 1998 5,794,982 H. J. Green, et al. Aug. 18, 1998
Of these patents, the '476 patent issued to Wagner discloses a method for securing a threaded coupling to the end of a flexible hose. A cup-shaped body is placed over the end of the flexible hose and defines an opening to cooperate with the opening of the hose. A tubular member defines an enlarged portion proximate one end and a threaded portion proximate the opposite end. The enlarged portion is inserted into the flexible hose leaving at least a portion of the threaded portion exposed. A tubular pressure element is then inserted over the tubular member up to the enlarged portion and into the flexible hose. A nut is then engaged with the threaded portion and tightened to draw the enlarged portion of the tubular member into the tubular pressure element. The cup-shaped body serves to retain the flexible hose as pressure is exerted by the tubular pressure element as a result of the nut being tightened. While being useful to secure a threaded nipple to the end of a flexible hose, the device taught by Wagner does not allow for the coupling of a rigid pipe to a flexible conduit.
Oetiker ('323) teaches a high pressure coupling specifically designed for use with hydraulic hoses of the type having inner and outer rubber layers and a reinforcement layer interposed therebetween. The '323 device includes a nipple structure which defines a number of annular ribs. An outer sleeve defines cooperating annular grooves. The nipple structure is inserted into the terminal portion of the hydraulic hose, and the outer sleeve is placed over the reinforcement layer of the hose. A portion of the outer rubber layer of the hose is removed. After the nipple structure and the outer sleeve are in place, the end of the outer sleeve is deformed to engage the nipple structure in order to maintain the device on the hose. However, the '323 device fails to teach a means for coupling a rigid pipe having no preformed deformations to a flexible conduit.
The '460 device, also taught by Oetiker, is a hose connection for high pressure installations. The '460 device includes an internal pipe over which is inserted a washer, and an outer sleeve. The outer sleeve is also received over the washer. The internal pipe is deformed to define a plurality of annular rings, the overall diameter being smaller than the internal diameter of the flexible hose to be coupled thereto. The hose is inserted over the internal pipe, into the outer sleeve, and to the washer. The internal pipe is then enlarged to engage the interior of the hose. The outer sleeve is then deformed to cover the washer at one end, and to define inward annular rings to cooperate with the deformations of the internal pipe. Specifically, the outward deformations of the internal pipe and the inward deformations of the outer sleeve alternate. This method of coupling the internal pipe to the flexible hose is complicated, especially in low pressure applications.
Bartholomew ('718) teaches a connector fitting positionable on the terminal end of a flexible conduit. The '718 device includes a first member positioned about the exterior surface of the terminal end of the conduit, and a second member positioned within the interior of the terminal end of the conduit. Once in position, the diameter of the second member is expanded to engage the interior surfitce of the conduit, and the terminal end of the first member is reduced to engage the outer surface of the conduit. The '718 device does not, however, teach a device for coupling a rigid pipe to a flexible conduit.
Sanders, et al. ('050), teach a coupling for a hose construction for use with a hose having an inner corrugated hose having inward projections. The '050 device defines an annular receptor for receiving the terminal end of the hose. A fitting defines a cooperating outer surface for being received by the corrugated inner surface of the hose, and an inner surface for cooperating with the interior wall of the coupling. Sanders, et al., do not teach a device for coupling a rigid pipe to a flexible conduit.
The '740 device disclosed by Fukaya, et al., teaches a structure for coupling a small-diameter thin metal tube to a pressure rubber hose. The metal tube is first fit with an inner tube and the two are deformed to define annular grooves. The rubber hose is then fit over the tube structure and is then caulked. Such a structure, by virtue of the requirement of caulking, is not an acceptable device for most coupling applications.
Green, et al. ('982), teach a device for coupling pipes with liners, the coupling device being provided with a liner. As in the '740 device above, the '982 device relies on a sealant compound to form a seal to prevent fluid communication between the coupler and the pipe or pipes into which the coupler is inserted. Green, et al., do not teach a device or method for coupling a rigid pipe to a flexible hose.
These prior art devices teach various methods for manipulating the end of a flexible hose, such as to provide a connecting terminal end, or to connect it to another conduit. However, the prior art discussed does not teach a simple method for coupling a rigid pipe to a flexible hose, while also providing a device which prevents fluid communication between the pipe and the hose. Further, this prior aft does not teach a device for coupling these components for low pressure applications.
Therefore, it is an object of this invention to provide a device for coupling a rigid pipe to a flexible conduit.
Another object of the present invention is to provide such a device for use in low pressure applications and for relatively large diameter pipes and conduits.
Yet another object of the present invention is to provide such a device whereby fluid communication between the rigid pipe and the flexible conduit is prevented.
Still another object of the present invention is to provide a method whereby such a device is fabricated and installed.